Instagram has silently released a payment option to some users which have not been officially announced yet. It comes after Facebook added a payment feature to Messenger, so it makes sense that they would add the same feature to Instagram.
Slash Gear which was one of the few profiles that have access to this feature said that the feature is very basic for now. The settings are located in the profile settings under the Payment Settings option, it allows you to add a debit or credit card and lets you add a PIN which is the second stage of security. The company has already put some plans in motion for this feature like allowing users to buy movie tickets and other things directly from the app. Brands can also showcase their products and take advantage of this feature as a payment gateway for their online stores.